package com.handpay.nocardpay.baselibrary.crypto;

public class DesEncrypt
{
	// 声明常量
	static final int[]		IP			= { 
		58, 50, 42, 34, 26, 18, 10, 2, 
		60, 52, 44, 36, 28, 20, 12, 4, 
		62, 54, 46, 38, 30, 22, 14, 6, 
		64, 56, 48, 40, 32, 24, 16, 8, 
		57, 49, 41, 33, 25, 17,  9, 1,
		59, 51, 43, 35, 27, 19, 11, 3, 
		61, 53, 45, 37, 29, 21, 13, 5, 
		63, 55, 47, 39, 31, 23, 15, 7 
	};	//64   
	static final int[]		IP_1		= { 
		40, 8, 48, 16, 56, 24, 64, 32, 
		39, 7, 47, 15, 55, 23, 63, 31, 
		38, 6, 46, 14, 54, 22, 62, 30, 
		37, 5, 45, 13, 53, 21, 61, 29, 
		36, 4, 44, 12, 52, 20, 60, 28,
		35, 3, 43, 11, 51, 19, 59, 27, 
		34, 2, 42, 10, 50, 18, 58, 26, 
		33, 1, 41,  9, 49, 17, 57, 25 
	};	//64   
	static final int[]		PC_1		= { 
		57, 49, 41, 33, 25, 17, 9, 1, 
		58, 50, 42, 34, 26, 18, 10, 2, 
		59, 51, 43, 35, 27, 19, 11, 3, 
		60, 52, 44, 36, 63, 55, 47, 39, 
		31, 23, 15, 7, 62, 54, 46, 38,
		30, 22, 14, 6, 61, 53, 45, 37, 
		29, 21, 13, 5, 28, 20, 12, 4 
	};	//56   
	static final int[]		PC_2		= { 
		14, 17, 11, 24, 1, 5, 3, 28, 
		15, 6, 21, 10, 23, 19, 12, 4, 
		26, 8, 16, 7, 27, 20, 13, 2, 
		41, 52, 31, 37, 47, 55, 30, 40, 
		51, 45, 33, 48, 44, 49, 39, 56, 
		34,	53, 46, 42, 50, 36, 29, 32 
	};	//48   
	static final int[]		E			= { 
		32, 1, 2, 3, 4, 5, 4, 5, 
		6, 7, 8, 9, 8, 9, 10, 11, 
		12, 13, 12, 13, 14, 15, 16, 17, 
		16, 17, 18, 19, 20, 21, 20, 21, 
		22, 23, 24, 25, 24, 25, 26, 27, 
		28, 29,	28, 29, 30, 31, 32, 1 
	};	//48   
	static final int[]		P			= { 
		16, 7, 20, 21, 29, 12, 28, 17, 
		1, 15, 23, 26, 5, 18, 31, 10, 
		2, 8, 24, 14, 32, 27, 3, 9, 
		19, 13, 30, 6, 22, 11, 4, 25 
	};	//32   
	static final int[][][]	S_Box		= {
		{//S_Box[1]  
			{ 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7 }, 
			{ 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8 }, 
			{ 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0 },
			{ 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 }
		}, 
		{//S_Box[2]
			{ 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10 }, 
			{ 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5 }, 
			{ 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15 },
			{ 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 } 
		}, 
		{//S_Box[3]   
			{ 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8 }, 
			{ 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1 }, 
			{ 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7 },
			{ 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 } 
		}, 
		{//S_Box[4]  
			{ 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15 }, 
			{ 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9 }, 
			{ 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4 },
			{ 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 } 
		}, 
		{//S_Box[5]  
			{ 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9 }, 
			{ 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6 }, 
			{ 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14 },
			{ 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 } 
		}, 
		{//S_Box[6]   
			{ 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11 }, 
			{ 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8 }, 
			{ 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6 },
			{ 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 } 
		}, 
		{//S_Box[7] 
			{ 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1 }, 
			{ 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6 }, 
			{ 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2 },
			{ 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 } 
		}, 
		{//S_Box[8]  
			{ 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7 }, 
			{ 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2 }, 
			{ 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8 },
			{ 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 } 
		}    
	};
	static final int[]		LeftMove	= { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };																			//   ����λ���б�   

	public byte[] Des(byte[] des_key, byte[] des_data, int flag)
	{
		// 检测输入参数格式是否正确，错误直接返回空值（null）  
		if ((des_key.length != 8) || (des_data.length != 8) || ((flag != 1) && (flag != 0)))
		{
			return null;
		}
		// 处理加密解密过程
		int flags = flag;
		int[] keydata = new int[64];
		int[] timedata = new int[64];
		byte[] EncryptCode = new byte[8];
		int[][] KeyArray = new int[16][48];
		keydata = ReadDataToInt(des_key);
		timedata = ReadDataToInt(des_data);
		KeyInitialize(keydata, KeyArray);
		EncryptCode = Encrypt(timedata, flags, KeyArray);
		return EncryptCode;
	}

	private int KeyInitialize(int[] key, int[][] keyarray)
	{
		int i, j;
		int[] K0 = new int[56];
		// 特别注意：xxx[IP[i]-1]等类似变换  
		for (i = 0; i < 56; i++)
		{
			K0[i] = key[PC_1[i] - 1]; // 密钥进行PC-1变换
		}
		for (i = 0; i < 16; i++)
		{
			LeftBitMove(K0, LeftMove[i]);
			// 特别注意：xxx[IP[i]-1]等类似变换
			for (j = 0; j < 48; j++)
			{
				keyarray[i][j] = K0[PC_2[j] - 1]; // 生成子密钥keyarray[i][j]  
			}
		}
		return 0;
	}

	private byte[] Encrypt(int[] timeData, int flag, int[][] keyarray)
	{
		int i;
		byte[] encrypt = new byte[8];
		int flags = flag;
		int[] M = new int[64];
		int[] MIP_1 = new int[64];
		// 特别注意：xxx[IP[i]-1]等类似变换  
		for (i = 0; i < 64; i++)
		{
			M[i] = timeData[IP[i] - 1]; // 明文IP变换
		}
		if (flags == 1)
		{ // 加密   
			for (i = 0; i < 16; i++)
			{
				LoopF(M, i, flags, keyarray);
			}
		}
		else if (flags == 0)
		{ // 解密   
			for (i = 15; i > -1; i--)
			{
				LoopF(M, i, flags, keyarray);
			}
		}
		for (i = 0; i < 64; i++)
		{
			MIP_1[i] = M[IP_1[i] - 1]; // 进行IP-1运算 
		}
		GetEncryptInt(MIP_1, encrypt);
		// 返回加密数据   
		return encrypt;
	}

	private int[] ReadDataToInt(byte[] intdata)
	{
		// 将数据转换为二进制数，存储到数组
		int i, j;
		int[] IntDa = new int[8];
		for (i = 0; i < 8; i++)
		{
			IntDa[i] = intdata[i];
			if (IntDa[i] < 0)
			{
				IntDa[i] += 256;
				IntDa[i] %= 256;
			}
		}
		int[] IntVa = new int[64];
		for (i = 0; i < 8; i++)
		{
			for (j = 0; j < 8; j++)
			{
				IntVa[((i * 8) + 7) - j] = IntDa[i] % 2;
				IntDa[i] = IntDa[i] / 2;
			}
		}
		return IntVa;
	}

	private int LeftBitMove(int[] k, int offset)
	{
		// 循环移位操作函数   
		int i;
		int[] c0 = new int[28];
		int[] d0 = new int[28];
		int[] c1 = new int[28];
		int[] d1 = new int[28];
		for (i = 0; i < 28; i++)
		{
			c0[i] = k[i];
			d0[i] = k[i + 28];
		}
		if (offset == 1)
		{
			for (i = 0; i < 27; i++)
			{ // 循环左移一位  
				c1[i] = c0[i + 1];
				d1[i] = d0[i + 1];
			}
			c1[27] = c0[0];
			d1[27] = d0[0];
		}
		else if (offset == 2)
		{
			for (i = 0; i < 26; i++)
			{ // 循环左移两位   
				c1[i] = c0[i + 2];
				d1[i] = d0[i + 2];
			}
			c1[26] = c0[0];
			d1[26] = d0[0];
			c1[27] = c0[1];
			d1[27] = d0[1];
		}
		for (i = 0; i < 28; i++)
		{
			k[i] = c1[i];
			k[i + 28] = d1[i];
		}
		return 0;
	}

	private int LoopF(int[] M, int times, int flag, int[][] keyarray)
	{
		int i, j;
		int[] L0 = new int[32];
		int[] R0 = new int[32];
		int[] L1 = new int[32];
		int[] R1 = new int[32];
		int[] RE = new int[48];
		int[][] S = new int[8][6];
		int[] sBoxData = new int[8];
		int[] sValue = new int[32];
		int[] RP = new int[32];
		for (i = 0; i < 32; i++)
		{
			L0[i] = M[i]; // 明文左侧的初始化  
			R0[i] = M[i + 32]; // 明文右侧的初始化 
		}
		for (i = 0; i < 48; i++)
		{
			RE[i] = R0[E[i] - 1]; // 经过E变换扩充，由32位变为48位   
			RE[i] = RE[i] + keyarray[times][i]; // 与KeyArray[times][i]按位作不进位加法运算
			if (RE[i] == 2)
			{
				RE[i] = 0;
			}
		}
		for (i = 0; i < 8; i++)
		{// 48位分成8组  
			for (j = 0; j < 6; j++)
			{
				S[i][j] = RE[(i * 6) + j];
			}
			// 下面经过S盒，得到8个数   
			sBoxData[i] = S_Box[i][(S[i][0] << 1) + S[i][5]][(S[i][1] << 3) + (S[i][2] << 2) + (S[i][3] << 1) + S[i][4]];
			// 8个数变换输出二进制   
			for (j = 0; j < 4; j++)
			{
				sValue[((i * 4) + 3) - j] = sBoxData[i] % 2;
				sBoxData[i] = sBoxData[i] / 2;
			}
		}
		for (i = 0; i < 32; i++)
		{
			RP[i] = sValue[P[i] - 1]; // 经过P变换
			L1[i] = R0[i]; // 右边移到左边   
			R1[i] = L0[i] + RP[i];

			if (R1[i] == 2)
			{
				R1[i] = 0;
			}
			// 重新合成M，返回数组M 
			// 最后一次变换时，左右不进行互换。此处采用两次变换实现不变  
			if (((flag == 0) && (times == 0)) || ((flag == 1) && (times == 15)))
			{
				M[i] = R1[i];
				M[i + 32] = L1[i];
			}
			else
			{
				M[i] = L1[i];
				M[i + 32] = R1[i];
			}
		}
		return 0;
	}

	private int GetEncryptInt(int[] data, byte[] value)
	{
		// 将存储64位二进制数据的数组中的数据转换为八个整数（byte）
		int i, j;
		for (i = 0; i < 8; i++)
		{
			for (j = 0; j < 8; j++)
			{
				value[i] += (data[(i << 3) + j] << (7 - j));
			}
		}
		for (i = 0; i < 8; i++)
		{
			value[i] %= 256;
			if (value[i] > 128)
			{
				value[i] -= 255;
			}
		}
		return 0;
	}
}
